JP2008165218A - Chemically amplified resist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemically amplified resist composition showing excellent resolution and giving excellent line edge roughness. <P>SOLUTION: The chemically amplified resist composition comprises: an acid generator comprising an onium salt represented by formula (I) and a sulfonium salt represented by formula (II); and a resin which contains a polymerized unit having an acid-labile group and which itself is insoluble or poorly soluble in an aqueous alkali solution but becomes soluble in an aqueous alkali solution by the action of an acid. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a chemically amplified resist composition used for semiconductor microfabrication.

A chemically amplified resist composition used for microfabrication of a semiconductor using a lithography technique has a polymerized unit having an acid labile group, and is itself insoluble or hardly soluble in an alkali. And an acid generator comprising a resin that is soluble in alkali and a compound that generates an acid upon exposure.
As a chemically amplified resist composition in microfabrication of semiconductors, there is a demand for a composition that exhibits superior resolution and excellent line edge roughness.

  Recently, it has a polymer unit having an acid labile group and itself is insoluble or hardly soluble in alkali, but becomes soluble in alkali by the action of acid, and triphenylsulfonium 4 as an acid generator. A chemically amplified positive resist composition using only -oxo-1-adamantyloxycarbonyldifluoromethanesulfonate and further comprising a quencher and a solvent has been proposed (Patent Document 1).

JP-A-2006-257078 Claims 1 and 15

  However, the performance of the resist composition described in Patent Document 1, such as resolution and line edge roughness, may not always be adequately met depending on various conditions such as the conditions during exposure and the conditions during development.

  In order to solve the above problems, the present inventors have intensively studied the acid generator contained in the chemically amplified resist composition. As a result, the present inventors have developed an acid containing two or more specific compounds as the acid generator. By using the generator, it was found that a chemically amplified resist composition showing excellent resolution and excellent line edge roughness was obtained, and the present invention was achieved.

  That is, the present invention has an acid generator containing an onium salt represented by the following formula (I) and a sulfonium salt represented by the formula (II), and a polymer unit having an acid-labile group. In addition, the present invention provides a chemically amplified resist composition characterized by containing a resin that is insoluble or hardly soluble in alkali but becomes soluble in alkali by the action of an acid.

[In the formula (I), R ²¹ represents a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may be substituted, or a cyclic carbon atom having 3 to 30 carbon atoms which may be substituted. Represents a hydrogen group. However, the carbon atom contained in the hydrocarbon group and the cyclic hydrocarbon group may be optionally substituted with a carbonyl group or an oxygen atom.
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
A ⁺ represents at least one cation selected from the group consisting of cations represented by formula (Ia), formula (Ib) and formula (Ic). ]

[In Formula (Ia), P ^{1 to} P ³ each independently represents a linear, branched or cyclic hydrocarbon group having 1 to 30 carbon atoms. When P ^{1 to} P ³ are linear or branched hydrocarbon groups, one or more of a hydroxyl group, an alkoxy group having 1 to 12 carbon atoms, or a cyclic hydrocarbon group having 3 to 12 carbon atoms is substituted. When P ^{1 to} P ³ are cyclic hydrocarbon groups, one or more of a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms may be substituted. It may be included as a group. The hydrocarbon group and the alkoxy group may be linear or branched.
In formula (Ib), P ⁴ and P ⁵ each independently represent a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the hydrocarbon group and the alkoxy group The group may be linear or branched.
In formula (Ic), P ^{10 to} P ²¹ each independently represent a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the hydrocarbon group and the alkoxy group The group may be linear or branched.
B represents a sulfur atom or an oxygen atom.
m represents 0 or 1. ]

[In the formula (II), R ²² represents a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may be substituted, or a cyclic carbon atom having 3 to 30 carbon atoms which may be substituted. Represents a hydrogen group. However, the carbon atom contained in the hydrocarbon group and the cyclic hydrocarbon group may be optionally substituted with a carbonyl group or an oxygen atom.
Q ³ and Q ⁴ each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
B ⁺ represents a cation represented by the formula (II ′). ]

[In Formula (II ′), P ⁶ and P ⁷ each independently represent a linear, branched or cyclic hydrocarbon group having 1 to 12 carbon atoms. Or ^{P 6} and ^{P 7} are bonded represent a divalent hydrocarbon group having 3 to 12 carbon atoms.
P ⁸ represents a hydrogen atom.
P ⁹ represents an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an optionally substituted aromatic ring group, or P ⁸ and P ⁹ are bonded to form 3 to 3 carbon atoms. 12 divalent hydrocarbon groups are represented. Here, the carbon atom contained in the divalent hydrocarbon group may be optionally substituted with a carbonyl group, an oxygen atom, or a sulfur atom. ]

  According to the chemically amplified resist composition of the present invention, a pattern having excellent resolution and excellent line edge roughness can be produced. Therefore, the present invention is extremely useful industrially.

  The chemically amplified resist composition of the present invention uses an onium salt represented by the formula (I) and a sulfonium salt represented by the formula (II) as an acid generator.

[In the formula (I), R ²¹ represents a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may be substituted, or a cyclic carbon atom having 3 to 30 carbon atoms which may be substituted. Represents a hydrogen group. However, the carbon atom contained in the hydrocarbon group and the cyclic hydrocarbon group may be optionally substituted with a carbonyl group or an oxygen atom.
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
A ⁺ represents at least one cation selected from the group consisting of cations represented by formula (Ia), formula (Ib) and formula (Ic). ]

[In Formula (Ia), P ^{1 to} P ³ each independently represents a linear, branched or cyclic hydrocarbon group having 1 to 30 carbon atoms. When P ^{1 to} P ³ are linear or branched hydrocarbon groups, one or more of a hydroxyl group, an alkoxy group having 1 to 12 carbon atoms, or a cyclic hydrocarbon group having 3 to 12 carbon atoms is substituted. When P ^{1 to} P ³ are cyclic hydrocarbon groups, one or more of a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms may be substituted. It may be included as a group. The hydrocarbon group and the alkoxy group may be linear or branched.
In formula (Ib), P ⁴ and P ⁵ each independently represent a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the hydrocarbon group and the alkoxy group The group may be linear or branched.
In formula (Ic), P ^{10 to} P ²¹ each independently represent a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the hydrocarbon group and the alkoxy group The group may be linear or branched.
B represents a sulfur atom or an oxygen atom.
m represents 0 or 1. ]

[In the formula (II), R ²² represents a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may be substituted, or a cyclic carbon atom having 3 to 30 carbon atoms which may be substituted. Represents a hydrogen group. However, the carbon atom contained in the hydrocarbon group and the cyclic hydrocarbon group may be optionally substituted with a carbonyl group or an oxygen atom.
Q ³ and Q ⁴ each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
D ⁺ represents a cation represented by the formula (II ′). ]

[In Formula (II ′), P ⁶ and P ⁷ each independently represent a linear, branched or cyclic hydrocarbon group having 1 to 12 carbon atoms. Or ^{P 6} and ^{P 7} are bonded represent a divalent hydrocarbon group having 3 to 12 carbon atoms.
P ⁸ represents a hydrogen atom.
P ⁹ represents a linear, branched or cyclic hydrocarbon group having 1 to 12 carbon atoms or an optionally substituted aromatic ring group, or P ⁸ and P ⁹ are bonded to form 3 to 3 carbon atoms. 12 divalent hydrocarbon groups are represented. Here, the carbon atom contained in the divalent hydrocarbon group may be optionally substituted with a carbonyl group, an oxygen atom, or a sulfur atom. ]

Examples of the linear, branched or cyclic hydrocarbon group having 1 to 30 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, Decyl group, undecyl group, dodecyl group, tridecanyl group, tetradecanyl group, pentadecanyl group, hexadecanyl group, heptadecanyl group, octadecanyl group, nonadecanyl group, icosanyl group, henicosanyl group, docosanyl group, henicosanyl group, dosanyl group, tricosanyl group, tetracosanyl group , Pentacosanyl group, hexacosanyl group, heptacosanyl group, octacosanyl group, nonacosanyl group, triacontanyl group and structural isomers of each of the above groups;
Examples include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclononyl group.
Examples of the linear or branched hydrocarbon group having 1 to 20 carbon atoms which may be substituted include, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl Group, nonyl group, decyl group, undecyl group, dodecyl group, tridecanyl group, tetradecanyl group, pentadecanyl group, hexadecanyl group, heptadecanyl group, octadecanyl group, nonadecanyl group, icosanyl group, henicosanyl group, docosanyl group and the structural isomerism of each of the above groups body;
Hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, hydroxyheptyl, hydroxyoctyl, hydroxynonyl, hydroxydecyl, hydroxyundecyl, hydroxydodecyl, hydroxy Tridecanyl group, hydroxytetradecanyl group, hydroxypentadecanyl group, hydroxyhexadecanyl group, hydroxyheptadecanyl group, hydroxyoctadecanyl group, hydroxynonadecanyl group, hydroxyicosanyl group and each of the above groups Structural isomers of
Dihydroxymethyl, dihydroxyethyl, dihydroxypropyl, dihydroxybutyl, dihydroxypentyl, dihydroxyhexyl, dihydroxyheptyl, dihydroxyoctyl, dihydroxynonyl, dihydroxydecyl, dihydroxyundecyl, dihydroxydodecyl, dihydroxy Tridecanyl group, dihydroxytetradecanyl group, dihydroxypentadecanyl group, dihydroxyhexadecanyl group, dihydroxyheptadecanyl group, dihydroxyoctadecanyl group, dihydroxynonadecanyl group, dihydroxyicosanyl group and each of the above groups And the structural isomers.

  Examples of the anion moiety of the salt represented by the formula (I) include anions represented by the following formula.

In Formula (I), A ⁺ is preferably at least one cation selected from the group consisting of cations represented by any one of Formula (Ia), Formula (Ib), or Formula (Ic). .

[In Formula (Ia), P ^{1 to} P ³ each independently represents a linear, branched or cyclic hydrocarbon group having 1 to 30 carbon atoms. P ¹ if to P ³ is a linear or branched hydrocarbon group, a hydroxyl group, one or more of the substituents of the cyclic hydrocarbon group having 3 to 12 alkoxy group or a carbon number of 1 to 12 carbon atoms In the case where P ^{1 to} P ³ are cyclic hydrocarbon groups, one or more of a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms may be substituted. May be included. The hydrocarbon group and the alkoxy group may be linear or branched.
In formula (Ib), P ⁴ and P ⁵ each independently represent a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the hydrocarbon group and the alkoxy group The group may be linear or branched.
In formula (Ic), P ^{10 to} P ²¹ each independently represent a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the hydrocarbon group and the alkoxy group The group may be linear or branched.
B represents a sulfur atom or an oxygen atom.
m represents 0 or 1. ]

Examples of the linear, branched or cyclic hydrocarbon group having 1 to 30 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and tert-butyl. Group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group, cyclopentyl group, cyclohexyl group, adamantyl group, bicyclohexyl group, phenyl group, naphthyl group, fluorenyl group, biphenyl group and the like.
Examples of the hydrocarbon group having 1 to 12 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, n- A heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-dodecyl group, 2-ethylhexyl group, etc. are mentioned.
Examples of the alkoxy group having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group and the like.
Examples of the cyclic hydrocarbon group having 3 to 12 carbon atoms include a cyclopentyl group, a cyclohexyl group, an adamantyl group, a bicyclohexyl group, a phenyl group, a naphthyl group, a fluorenyl group, and a biphenyl group. The cyclic hydrocarbon group may be substituted with a linear or branched hydrocarbon group, an alkoxy group, a hydroxyl group, an amino group, or the like.

  Examples of the cation represented by the formula (Ia) include a cation represented by the following formula.

  Examples of the cation represented by the formula (Ib) include a cation represented by the following formula.

  Examples of the cation represented by the formula (Ic) include a cation represented by the following formula.

Further, the cation represented by A ⁺ is preferably at least one cation selected from the group consisting of cations represented by any one of formula (Id), formula (Ie) and formula (If).

[In Formula (Id) to Formula (If), P ^{28 to} P ³⁰ each independently represents a linear or branched hydrocarbon group having 1 to 20 carbon atoms, or 3 carbon atoms other than a phenyl group. Represents 30 cyclic hydrocarbon groups. If P ²⁸ to P ³⁰ is a hydrocarbon group, a hydroxyl group may comprise as one or more substituents of the cyclic hydrocarbon group having 3 to 12 alkoxy group or a carbon number of 1 to 12 carbon atoms, If P ²⁸ to P ³⁰ is a cyclic hydrocarbon group, a hydroxyl group, it may be included as one or more of the substituents of the hydrocarbon group or an alkoxy group having 1 to 12 carbon atoms having 1 to 12 carbon atoms.
P ^{31 to} P ³⁶ each independently represent a hydroxyl group, a linear, branched or cyclic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
g, h, i, j, k and l each independently represent an integer of 0 to 5. ]

  g, h, i, j, k and l each independently preferably represent an integer of 0 to 2, more preferably an integer of 0 to 1.

  Furthermore, as the cation represented by the formula (Ia), the cation represented by the formula (Ig) is more preferable because the production thereof is easy.

[In Formula (Ig), P ^{41 to} P ⁴³ each independently represents a hydrogen atom, a hydroxyl group, a linear or branched hydrocarbon group having 1 to 12 carbon atoms, or a linear or branched carbon number of 1; Represents an alkoxy group of ˜12. ]

Examples of the linear or branched hydrocarbon group having 1 to 12 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, and pentyl group. Hexyl group, octyl group, 2-ethylhexyl group and the like.
Examples of the linear or branched alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, an octyloxy group, and a 2-ethylhexyloxy group.

  Furthermore, as the cation represented by the formula (Ig), the cation represented by the formula (Ih) is more preferable because it is easier to produce.

[In Formula (Ih), P ^{22 to} P ²⁴ each independently represents a hydrogen atom or a linear or branched hydrocarbon group having 1 to 4 carbon atoms. ]

  And as an onium salt represented by the formula (I) of this invention, the onium salt represented by a formula (Ii), a formula (Ij), or a formula (Ik) is especially preferable.

[In formula (Ii), formula (Ij) and formula (Ik), Q ¹ and Q ² represent the same meaning as in formula (I).
P ^{22 to} P ²⁴ represent the same meaning as in formula (Ih).
Ring X represents a monocyclic or polycyclic hydrocarbon group having 3 to 30 carbon atoms. However, the carbon atom of the hydrocarbon group may be substituted with a carbonyl group.
Ring X is a hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, a hydroxyl group, or a cyano group. It may be included as a substituent.
Z ¹ represents a single bond or — [CH ₂ ] _k —.
k represents an integer of 1 to 4. ]

  Furthermore, an onium salt represented by the formula (Il), the formula (Im) or the formula (In) in which the ring X has an adamantane skeleton is preferable.

[In formula (Il), formula (Im) and formula (In), Q ¹ and Q ² represent the same meaning as in formula (I).
P ^{22 to} P ²⁴ represent the same meaning as in formula (Ih). ]

  The chemically amplified resist composition of the present invention further contains a sulfonium salt represented by the formula (II) as an acid generator.

[In the formula (II), R ²² represents a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may be substituted, or a cyclic carbon atom having 3 to 30 carbon atoms which may be substituted. Represents a hydrogen group. However, the carbon atom contained in the hydrocarbon group and the cyclic hydrocarbon group may be optionally substituted with a carbonyl group or an oxygen atom.
Q ³ and Q ⁴ each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
D ⁺ represents a cation represented by the formula (II ′). ]

[In Formula (II ′), P ⁶ and P ⁷ each independently represent a linear, branched or cyclic hydrocarbon group having 1 to 12 carbon atoms, or P ⁶ and P ⁷ are bonded to each other. Represents a divalent hydrocarbon group having 3 to 12 carbon atoms.
P ⁸ represents a hydrogen atom.
P ⁹ represents a linear, branched or cyclic hydrocarbon group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or an optionally substituted aromatic ring group, or P ⁸ P ⁹ is bonded to represent a C 3-12 divalent hydrocarbon group. Here, the carbon atom contained in the divalent hydrocarbon group may be optionally substituted with a carbonyl group, an oxygen atom, or a sulfur atom. ]

Examples of the linear or branched hydrocarbon group having 1 to 20 carbon atoms which may be substituted include the same ones as described above.
Examples of the C 1-6 perfluoroalkyl group are the same as those described above.
Q ³ and Q ⁴ are preferably each independently a fluorine atom or a trifluoromethyl group. Above ^all, when all Q 1 to Q ⁴ is a fluorine atom is more preferable.

  Examples of the anion moiety of the sulfonium salt represented by the formula (II) include the same anions as the anion moiety of the onium salt represented by the formula (I).

Examples of the hydrocarbon group having 1 to 12 carbon atoms in P ⁶ and P ⁷ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, Examples include hexyl group, octyl group, 2-ethylhexyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclodecyl group.
Further, by bonding P ⁶ and P ^7, it may be a divalent hydrocarbon group having 3 to 12 carbon atoms such as an alkylene group.
P ⁸ represents a hydrogen atom. P ⁹ represents an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aromatic ring group which may be substituted such as a phenyl group or a benzyl group, or P ⁸ and P ⁹ are A divalent hydrocarbon group having 3 to 12 carbon atoms such as an alkylene group is bonded. When P ⁹ is an alkyl group, specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. Group, octyl group, 2-ethylhexyl group and the like. When P ⁹ is a cycloalkyl group, examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclodecyl group. Here, the carbon atom contained in the divalent hydrocarbon group in the formula (II ′) may be optionally substituted with a carbonyl group, an oxygen atom, or a sulfur atom.

Examples of the cation A ⁺ represented by the formula (II ′) include a cation represented by the following formula.

  And as a sulfonium salt represented by Formula (II), the sulfonium salt represented by (IIa), (IIb) or (IIc) is especially preferable.

[In formulas (IIa), (IIb) and (IIc), P ^{6 to} P ⁹ , Q ³ and Q ⁴ each independently represent the same meaning as in formula (II).
Ring X is a substituent of a hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, a hydroxyl group, or a cyano group. May be included.
Z represents a single bond or a — [CH ₂ ] _k — group.
k represents an integer of 1 to 4. ]

  Among these, a sulfonium salt represented by the formula (IId), the formula (IIf) or the formula (IIg) in which the ring X has an adamantane skeleton is preferable.

[In formula (IId), formula (IIe) and formula (IIf), Q ³ and Q ⁴ each independently represent the same meaning as in formula (II).
P ^{6 to} P ⁹ each independently represent the same meaning as in formula (II). ]

In the chemically amplified resist composition of the present invention, the use ratio of the onium salt represented by the formula (I) and the sulfonium salt represented by the formula (II) is a mass ratio, preferably 9: 1 to 1. : 9, more preferably 3: 7 to 6: 4, still more preferably 4: 6 to 6: 4, and even more preferably 4: 6 to 5: 5.
In this case, the onium salt represented by the formula (I) and the sulfonium salt represented by the formula (II) may be used alone or in combination.

  The chemically amplified resist composition of the present invention comprises a resin together with the acid generator, and the resin has an acid labile group and is an insoluble or hardly soluble resin in an alkaline aqueous solution. The resin is a resin that can be dissolved in an aqueous alkaline solution by the action. Here, an acid labile group represents a group that exhibits an effect that can be dissolved in an aqueous alkaline solution by the action of an acid.

  In the chemically amplified resist composition of the present invention, the onium salt represented by the formula (I) and the sulfonium salt represented by the formula (II) are used as an acid generator, and the acid generated by exposure is a resin. The resin is cleaved by catalytically acting on an acid-labile group therein, and the resin becomes soluble in an alkaline aqueous solution.

Examples of the acid labile group include a group having an alkyl ester in which the α position of the ether bond is a quaternary carbon atom, a group having a carboxylic acid ester such as an alicyclic ester, and the α position of the ether bond in a quaternary carbon atom. And a group having a lactone ring.
Here, the quaternary carbon atom means a carbon atom bonded to a substituent other than a hydrogen atom and not bonded to hydrogen, and an acid labile group is a carbon at the α-position of an ether bond. It is preferred that the atom is a quaternary carbon atom bonded to three carbon atoms.

When a group having a carboxylic acid ester which is one of acid labile groups is exemplified as an R ester group of —COOR, (—COO—C (CH ₃ ) ₃ is referred to as a tert-butyl ester group. ), An alkyl ester group in which the α-position of the ether bond represented by the tert-butyl ester group is a quaternary carbon atom; a methoxymethyl ester group, an ethoxymethyl ester group, a 1-ethoxyethyl ester group, a 1-isobutoxyethyl ester Group, 1-isopropoxyethyl ester group, 1-ethoxypropyl ester group, 1- (2-methoxyethoxy) ethyl ester group, 1- (2-acetoxyethoxy) ethyl ester group, 1- [2- (1-adamantyl) Oxy) ethoxy] ethyl ester group, 1- [2- (1-adamantanecarbonyloxy) ethoxy] ethyl Acetal-type ester groups such as a ruester group, a tetrahydro-2-furyl ester group and a tetrahydro-2-pyranyl ester group; an isobornyl ester group and a 1-alkylcycloalkyl ester group, a 2-alkyl-2-adamantyl ester group, 1 And an alicyclic ester group in which the α-position of the ether bond such as a-(1-adamantyl) -1-alkylalkyl ester group is a quaternary carbon atom.

  Examples of the group having a carboxylic acid ester include a group having a (meth) acrylic acid ester, a norbornene carboxylic acid ester, a tricyclodecene carboxylic acid ester, and a tetracyclodecene carboxylic acid ester.

The resin of the resin composition of the present invention can be produced by addition polymerization of a monomer having an acid labile group and an olefinic double bond.
Such monomers include bulky groups such as alicyclic structures such as 2-alkyl-2-adamantyl groups and 1- (1-adamantyl) -1-alkylalkyl groups as acid labile groups. Monomers are preferred because the resolution of the resulting resist tends to be excellent.
Examples of the monomer containing a bulky group include 2-alkyl-2-adamantyl (meth) acrylate, 1- (1-adamantyl) -1-alkylalkyl (meth) acrylate, and 5-norbornene-2-carboxylic acid. 2-alkyl-2-adamantyl, 5-norbornene-2-carboxylic acid 1- (1-adamantyl) -1-alkylalkyl, α-chloroacrylic acid 2-alkyl-2-adamantyl, α-chloroacrylic acid 1- ( 1-adamantyl) -1-alkylalkyl and the like.

  Among them, when 2-alkyl-2-adamantyl (meth) acrylate or 2-alkyl-2-adamantyl α-chloroacrylate is used as a monomer, the resolution of the chemically amplified resist composition obtained tends to be excellent. This is preferable.

  Examples of (meth) acrylic acid 2-alkyl-2-adamantyl include 2-methyl-2-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl acrylate, and methacrylic acid 2 -Ethyl-2-adamantyl, 2-n-butyl-2-adamantyl acrylate, and the like. Examples of α-chloroacrylate 2-alkyl-2-adamantyl include α-chloroacrylate 2-methyl-2 -Adamantyl, 2-ethyl-2-adamantyl α-chloroacrylate and the like.

  Among these, when 2-ethyl-2-adamantyl (meth) acrylate or 2-isopropyl-2-adamantyl (meth) acrylate is used, the sensitivity of the resulting chemically amplified resist composition is excellent and the heat resistance is also excellent. It is preferable because of its tendency.

  (Meth) acrylic acid 2-alkyl-2-adamantyl can be usually produced by a reaction of 2-alkyl-2-adamantanol or a metal salt thereof with acrylic acid halide or methacrylic acid halide.

The resin used in the present invention may contain a structural unit derived from a monomer that is stable against the action of an acid, in addition to a structural unit derived from a monomer having an acid labile group. Here, the structure derived from a monomer that is stable against the action of an acid means a structure that is not cleaved by the onium salt (I) of the present invention.
Specifically, a structural unit derived from a monomer having a free carboxylic acid group such as acrylic acid or methacrylic acid, or a structural unit derived from an aliphatic unsaturated dicarboxylic anhydride such as maleic anhydride or itaconic anhydride , Structural units derived from 2-norbornene, structural units derived from (meth) acrylonitrile, (meth) acrylic acid wherein the α-position of the ether bond is a secondary or tertiary carbon atom alkyl ester or 1-adamantyl ester Structural units derived from esters, structural units derived from styrenic monomers such as p- or m-hydroxystyrene, and structures derived from (meth) acryloyloxy-γ-butyrolactone in which the lactone ring may be substituted with an alkyl group Examples include units. The 1-adamantyl ester is a quaternary carbon atom at the α-position of the ether bond, but is an acid-labile group, and a hydroxyl group or the like may be bonded to the 1-adamantyl ester.

  Specific monomers that are stable against the action of acid include 3-hydroxy-1-adamantyl (meth) acrylate, 3,5-dihydroxy-1-adamantyl (meth) acrylate, and α- (meth) acryloyloxy- alicyclic compound having an olefinic double bond in the molecule such as γ-butyrolactone, β- (meth) acryloyloxy-γ-butyrolactone, formula (a), (b), hydroxystyrene, norbornene (c), anhydrous male Examples thereof include aliphatic unsaturated dicarboxylic acid anhydrides such as acid (d) and itaconic anhydride (e).

  Among these, structural units derived from styrene monomers such as p- or m-hydroxystyrene, structural units derived from 3-hydroxy-1-adamantyl (meth) acrylate, 3,5-dihydroxy (meth) acrylate A resist obtained from a resin containing a structural unit derived from -1-adamantyl, a structural unit represented by the formula (a), and a structural unit represented by the formula (b) has the following advantages: This is preferable because the image quality tends to improve.

[In Formula (a) and Formula (b), R ¹ and R ² each independently represents a hydrogen atom or a methyl group.
R ³ and R ⁴ each independently represents a hydrogen atom, a halogen atom, a methyl group or a trifluoromethyl group.
p and q each independently represent an integer of 1 to 3. When p is 2 or 3, R ³ may be a different group, and when q is 2 or 3, R ⁴ may be a different group. ]

  Monomers such as 3-hydroxy-1-adamantyl (meth) acrylate and 3,5-dihydroxy-1-adamantyl (meth) acrylate are commercially available. For example, the corresponding hydroxyadamantane is converted to (meth) acrylic acid. Or it can also manufacture by making it react with the halide.

  In addition, a monomer such as (meth) acryloyloxy-γ-butyrolactone is obtained by reacting α- or β-bromo-γ-butyrolactone whose lactone ring may be substituted with an alkyl group with acrylic acid or methacrylic acid, or lactone. It can be produced by reacting an α- or β-hydroxy-γ-butyrolactone whose ring may be substituted with an alkyl group with an acrylic acid halide or a methacrylic acid halide.

  As a monomer which gives the structural unit represented by Formula (a) and Formula (b), the (meth) acrylic acid ester of the alicyclic lactone which has the following hydroxyl groups, mixtures thereof, etc. are mentioned, for example. These esters can be produced, for example, by a reaction between a corresponding alicyclic lactone having a hydroxyl group and (meth) acrylic acid (for example, JP-A No. 2000-26446).

  Here, as (meth) acryloyloxy-γ-butyrolactone, for example, α-acryloyloxy-γ-butyrolactone, α-methacryloyloxy-γ-butyrolactone, α-acryloyloxy-β, β-dimethyl-γ-butyrolactone, α- Methacryloyloxy-β, β-dimethyl-γ-butyrolactone, α-acryloyloxy-α-methyl-γ-butyrolactone, α-methacryloyloxy-α-methyl-γ-butyrolactone, β-acryloyloxy-γ-butyrolactone, β- Examples include methacryloyloxy-γ-butyrolactone, β-methacryloyloxy-α-methyl-γ-butyrolactone, and the like.

  In the case of KrF excimer laser exposure, sufficient transmittance can be obtained even if a structural unit derived from a styrene monomer such as p- or m-hydroxystyrene is used as the structural unit of the resin. Such a copolymer resin can be obtained by radical polymerization of the corresponding (meth) acrylic acid ester monomer, acetoxystyrene, and styrene, followed by deacetylation by the action of an acid.

  In addition, a resin containing a structural unit derived from 2-norbornene has a norbornane skeleton in its main chain, so that it has a sturdy structure and excellent dry etching resistance. The structural unit derived from 2-norbornene can be introduced into the main chain by radical polymerization using, in addition to the corresponding 2-norbornene, an aliphatic unsaturated dicarboxylic anhydride such as maleic anhydride or itaconic anhydride. . Therefore, what is formed by opening the double bond of the norbornene structure can be represented by, for example, the formula (c), and formed by opening the double bond of maleic anhydride and itaconic anhydride. Things can be represented by formula (d) and formula (e), respectively.

[In formula (c), R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a carboxyl group, a cyano group or a group —COOU (U is an alcohol residue). Alternatively, R ⁵ and R ⁶ are bonded to each other to represent a carboxylic acid anhydride residue represented by —C (═O) OC (═O) —.
When R ⁵ and R ⁶ are a group —COOU, a carboxyl group is an ester bond, and examples of the alcohol residue corresponding to U include carbon atoms having about 1 to 8 carbon atoms which may be substituted. Examples thereof include a hydrogen group, a 2-oxooxolan-3-yl group, and a 2-oxooxolan-4-yl group. Here, in the hydrocarbon group, a hydroxyl group, an alicyclic hydrocarbon residue, or the like may be bonded as a substituent. ]

Specific examples when R ⁵ and R ⁶ are hydrocarbon groups include a methyl group, an ethyl group, a propyl group, and the like. Specific examples of the alkyl group to which a hydroxyl group is bonded include a hydroxymethyl group, 2-hydroxy group. An ethyl group etc. are mentioned.

Thus, specific examples of the norbornene structure represented by the formula (c), which is a monomer that gives an acid-labile structural unit, include the following compounds.
2-norbornene,
2-hydroxy-5-norbornene,
5-norbornene-2-carboxylic acid,
Methyl 5-norbornene-2-carboxylate,
2-hydroxy-1-ethyl 5-norbornene-2-carboxylate,
5-norbornene-2-methanol,
5-norbornene-2,3-dicarboxylic anhydride.

In addition, when U of —COOU of R ⁵ and R ⁶ in formula (c) is an acid-labile group such as an alicyclic ester in which the α position of the ether bond is a quaternary carbon atom, a norbornene structure Is a structural unit having an acid labile group. Examples of the monomer containing a norbornene structure and an acid labile group include, for example, 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene 2-carboxylate 1-methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl, 5-norbornene-2-carboxylic acid 1- (4-methylcyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1- (4-Oxocyclohexyl) ethyl, 5-norbornene-2-carboxylic acid 1- (1-adama) Nthyl) -1-methylethyl and the like.

  The resin used in the chemically amplified resist composition of the present invention varies depending on the type of radiation for patterning exposure and the type of acid labile group, but usually has an acid labile group in the resin. The content of the structural unit derived from the monomer is adjusted to a range of 10 to 80 mol%.

  Among them, as structural units derived from monomers having an acid labile group, 2-alkyl-2-adamantyl (meth) acrylate, 1- (1-adamantyl) -1-alkylalkyl (meth) acrylate The resin containing the structural unit derived from the above has a sturdy structure because the resin has an alicyclic group when the structural unit is 15 mol% or more of all the structural units constituting the resin, and the resist containing the resin This is advantageous in terms of dry etching resistance.

  In addition, when using an alicyclic compound having an olefinic double bond in the molecule and an aliphatic unsaturated dicarboxylic anhydride as monomers, these monomers tend to be difficult to undergo addition polymerization. These are preferably used in excess.

  Further, as the monomer used, monomers having the same olefinic double bond but different acid labile groups may be used in combination, or monomers having the same acid labile group but different olefinic double bonds may be used. You may use together, and you may use together the monomer from which the combination of an acid labile group and an olefinic double bond differs.

  When the above resin is used as a chemically amplified resist composition, a basic compound, preferably a basic nitrogen-containing organic compound, particularly preferably an amine or ammonium salt is contained. By adding a basic compound as a quencher, it is possible to improve the performance degradation due to the deactivation of the acid accompanying the holding after exposure. Specific examples of the basic compound used for the quencher include those represented by the following formulas.

[Wherein R ¹¹ , R ¹² and R ¹⁷ are each independently a hydrogen atom, a linear, branched or cyclic hydrocarbon group having about 1 to 10 carbon atoms or an aryl group having about 6 to 10 carbon atoms. Represents. Furthermore, at least one hydrogen atom on the hydrocarbon group or aryl group may be independently substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. . At least one hydrogen atom on the amino group may be independently substituted with an alkyl group having 1 to 4 carbon atoms.
R ^{13 to} R ¹⁵ are each independently a hydrogen atom, a linear, branched or cyclic hydrocarbon group having about 1 to 10 carbon atoms, an aryl group having about 6 to 10 carbon atoms, or about 1 to 6 carbon atoms. Represents an alkoxy group.
Furthermore, at least one hydrogen atom on the hydrocarbon group, aryl group, or alkoxy group is independently a hydroxyl group, an amino group, or an alkoxy group having about 1 to 6 carbon atoms. May be substituted. At least one of the hydrogen atoms on the amino group may be substituted with an alkyl group having 1 to 4 carbon atoms.
R ¹⁶ represents a linear, branched or cyclic hydrocarbon group having about 1 to 10 carbon atoms. Furthermore, at least one hydrogen atom on the hydrocarbon group may be independently substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. At least one hydrogen atom on the amino group may be substituted with a hydrocarbon group having 1 to 4 carbon atoms.
R ^{17 to} R ²⁰ each independently represent a linear, branched or cyclic hydrocarbon group having about 1 to 10 carbon atoms or an aryl group having about 6 to 10 carbon atoms. Furthermore, at least one hydrogen atom on the hydrocarbon group or aryl group may be independently substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. At least one hydrogen atom on the amino group may be substituted with a hydrocarbon group having 1 to 4 carbon atoms.
W represents an alkylene group having 1 to 10 carbon atoms, a carbonyl group, an imino group, a sulfide group or a disulfide group. The alkylene group preferably has about 2 to 6 carbon atoms. ]

  Specific examples of such compounds include hexylamine, heptylamine, octylamine, nonylamine, decylamine, aniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, 1- or 2-naphthylamine, and ethylenediamine. , Tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′- Diethyldiphenylmethane, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, N-methylaniline, piperidine, diphenylamine, triethylamine, trimethylamine, tripropylamine, tributylamine , Tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine Methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, N, N-dimethylaniline, 2,6-isopropylaniline, imidazole, pyridine, -Methylpyridine, 4-methylimidazole, bipyridine, 2,2'-dipyridylamine, di-2-pyridyl ketone, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,3-di (4-pyridyl) propane, 1,2-bis (2-pyridyl) ethylene, 1,2-bis (4-pyridyl) ethylene, 1,2-bis (4-pyridyloxy) ethane, 4 , 4′-dipyridyl sulfide, 4,4′-dipyridyl disulfide, 1,2-bis (4-pyridyl) ethylene, 2,2′-dipicolylamine, 3,3′-dipicolylamine, tetramethylammonium hydroxide Tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetra-n-hexylammonium hydroxide, tetra-n- Examples include octylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-trifluoromethylphenyltrimethylammonium hydroxide, (2-hydroxyethyl) trimethylammonium hydroxide (common name: choline), and the like.

  Furthermore, a hindered amine compound having a piperidine skeleton as disclosed in JP-A-11-52575 can be used as a quencher.

The chemically amplified resist composition of the present invention may contain about 80 to 99.9% by weight of resin and about 0.1 to 20% by weight of acid generator based on the total solid content. preferable.
Here, solid content means the total amount of the component remove | excluding the solvent from the chemically amplified resist composition.
Moreover, when using the basic compound which is a quencher for a chemically amplified resist composition, it is preferable to contain it in the range of about 0.01 to 1 weight% on the basis of the total solid content of the resist composition.
The chemically amplified resist composition may further contain small amounts of various additives such as sensitizers, dissolution inhibitors, other resins, surfactants, stabilizers, and dyes as necessary.

The chemically amplified resist composition of the present invention is usually a resist solution composition in a state where each of the above components is dissolved in a solvent, and is usually industrially applied to a substrate such as a silicon wafer such as spin coating. It is applied according to the method used.
The solvent used here may be any solvent that dissolves each resist component, has an appropriate drying speed, and gives a uniform and smooth coating film after the solvent evaporates, and is usually used industrially in this field. Can be used.

  Examples of the solvent include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate, glycol ethers such as propylene glycol monomethyl ether, ethyl lactate, butyl acetate, amyl acetate and pyruvin. Examples thereof include esters such as ethyl acid, ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone, and cyclic esters such as γ-butyrolactone. These solvents can be used alone or in combination of two or more.

  The resist film coated and dried on the substrate is subjected to an exposure process for patterning, followed by a heat treatment for promoting a deprotecting group reaction, and then developed with an alkali developer. The alkaline developer used here may be various alkaline aqueous solutions used in this field, but generally an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline) is used. Often used.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
In Examples and Comparative Examples, “%” and “part” representing content or use amount are based on weight unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography (HLC-8120GPC type manufactured by Tosoh Corporation, column is TSKgel Multipore HXL-M3, solvent is tetrahydrofuran) using polystyrene as a standard product.
The structure of the compound was confirmed by NMR (JEOL GX-270 type or EX-270 type) and mass spectrometry (LC: Agilent 1100 type, MASS: Agilent LC / MSD type or LC / MSD TOF type). .

Synthesis example of acid generator 1: Synthesis of triphenylsulfonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (acid generator B1) (1) 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester, 250 parts of ion-exchanged water In an ice bath, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise. The mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.8 parts of sodium difluorosulfoacetate (containing inorganic salt, purity 62.8%).
(2) Difluorosulfoacetate sodium salt 5.0 parts (purity 62.8%), 4-oxo-1-adamantanol 2.6 parts, ethylbenzene 100 parts, 0.8 part of concentrated sulfuric acid was added, and 30 hours Heated to reflux. After cooling, the mixture was filtered and washed with tert-butyl methyl ether to obtain 5.5 parts of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. As a result of purity analysis by ¹ H-NMR, the purity was 35.6%.

¹ H-NMR (dimethylsulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.84 (d, 2H, J = 13.0 Hz); 2.00 (d, 2H, J = 1.11. 9Hz); 2.29-2.32 (m, 7H); 2.54 (s, 2H)

(3) Difluorosulfoacetic acid-4-oxo-1-adamantyl ester 5.4 parts (purity 35.6%) of sodium salt was charged, and a mixed solvent of 16 parts acetonitrile and 16 parts ion-exchanged water was added. To this was added a solution of 1.7 parts triphenylsulfonium chloride, 5 parts acetonitrile, and 5 parts ion-exchanged water. After stirring for 15 hours, the mixture was concentrated and extracted with 142 parts of chloroform. The organic layer was washed with ion exchange water, and the obtained organic layer was concentrated. The concentrated solution was repulped with 24 parts of tert-butyl methyl ether to obtain 1.7 parts of triphenylsulfonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (B1) as a white solid.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.83 (d, 2H, J = 12.7 Hz); 2.00 (d, 2H, J = 12. 0Hz); 2.29-2.32 (m, 7H); 2.53 (s, 2H); 7.75-7.91 (m, 15H)
MS (ESI (+) Spectrum): M + 263.2 (C ₁₈ H ₁₅ S ⁺ = 263.09)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₂ H ₁₃ F ₂ O ₆ S ⁻ = 323.04)

Synthesis example of acid generator 2: Synthesis of triphenylsulfonium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate (acid generator B2) (1) 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester, ion exchange To 150 parts of water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.4 parts of sodium difluorosulfoacetate (containing inorganic salt, purity 62.7%).
(2) 1.0 part of 1,1′-carbonyldiimidazole was added to 1.9 parts of difluorosulfoacetate sodium salt (purity 62.7%) and 9.5 parts of N, N-dimethylformamide and stirred for 2 hours. did. To this solution, 0.2 parts of sodium hydride was added to 1.1 parts of 3-hydroxyadamantylmethanol and 5.5 parts of N, N-dimethylformamide and added to the solution stirred for 2 hours. After stirring for 15 hours, the produced difluorosulfoacetate-3-hydroxy-1-adamantyl methyl ester sodium salt was used as it was in the next reaction.

(3) To the solution of difluorosulfoacetic acid-3-hydroxy-1-adamantylmethyl ester sodium salt obtained in (2) above, 17.2 parts of chloroform and 2.9 parts of a 14.8% aqueous solution of triphenylsulfonium chloride were added. did. After stirring for 15 hours, the mixture was separated, and the aqueous layer was extracted with 6.5 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. To the concentrate was added 5.0 parts of tert-butyl methyl ether, and the mixture was stirred and filtered to give triphenylsulfonium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate (B2) as a white solid in an amount of 0. Two parts were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.38-1.51 (m, 12H); 2.07 (S, 2H); 3.85 (s , 2H); 4.41 (s, 1H); 7.75-7.89 (m, 15H)
MS of B2 (ESI (+) Spectrum): M + 263.07 (C ₁₈ H ₁₅ S ⁺ = 263.09)
MS (ESI (−) Spectrum): M− 339.10 (C ₁₃ H ₁₇ F ₂ O ₆ S ⁻ = 339.07)

Acid generator synthesis example 3: triphenylsulfonium 1- (hexahydro-2-oxo-3,5-methano-2H-cyclopenta [b] furan-6-yloxycarbonyl) difluoromethanesulfonate (acid generator B3) Synthesis (1) To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 250 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.8 parts of sodium difluorosulfoacetate (containing inorganic salt, purity 62.8%).
(2) Difluorosulfoacetic acid sodium salt 30.0 parts (purity 62.8%), hexahydro-6-hydroxy-3,5-methano-2H-cyclopenta [b] furan-2-one 14.7 parts, toluene 300 Then, 18.1 parts of p-toluenesulfonic acid (p-TsOH) was added and heated to reflux for 12 hours. Then, after filtration, 100 parts of acetonitrile was added to the residue, and the mixture was stirred and filtered, and concentrated to difluorosulfoacetate hexahydro-2-oxo-3,5-methano-2H-cyclopenta [b] furan-6-yl ester sodium salt. Of 26.7 parts.

¹ H-NMR (dimethylsulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.57-1.67 (m, 2H); 1.91-2.06 (m, 2H); 2 .53 (dd, 1H); 3.21 (td, 1H); 4.51 (d, 1H); 4.62 (s, 1H)

(3) 26.7 parts of difluorosulfoacetic acid hexahydro-2-oxo-3,5-methano-2H-cyclopenta [b] furan-6-yl ester sodium salt obtained in (2) above was charged and 267 parts of acetonitrile. Dissolved in. To this solution, 23.9 parts of triphenylsulfonium chloride and 239 parts of ion-exchanged water were added. After stirring for 15 hours, the mixture was concentrated and extracted twice with 200 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. By repulping the concentrate with 200 parts of tert-butyl methyl ether, triphenylsulfonium 1- (hexahydro-2-oxo-3,5-methano-2H-cyclopenta [b] furan-6-yloxy was obtained as a pale yellow oil. 37.7 parts of carbonyl) difluoromethanesulfonate (B3) were obtained.

¹ H-NMR (dimethylsulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.57-1.67 (m, 2H); 1.91-2.06 (m, 2H); 2 .53 (dd, 1H); 3.21 (td, 1H); 4.51 (d, 1H); 4.62 (s, 1H); 7.91-7.76 (m, 15H)
MS (ESI (+) Spectrum): M + 263.2 (C ₁₈ H ₁₅ S ⁺ = 263.09)
MS (ESI (−) Spectrum): M− 311.0 (C ₁₀ H ₉ F ₂ O ₇ S ⁻ = 311.00)

Acid generator synthesis example 4: Synthesis of methyldiphenylsulfonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (acid generator B4) (1) 200 parts of difluoro (fluorosulfonyl) acetic acid methyl ester, 300 parts of ion-exchanged water Then, 460 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The mixture was refluxed at 100 ° C. for 2.5 hours, cooled, and neutralized with 175 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 328.19 parts of difluorosulfoacetic acid sodium salt (the content was 62.8% because the inorganic salt was not removed).
(2) Difluorosulfoacetate sodium salt obtained in (1) 5.0 parts (content 62.8%), 4-oxo-1-adamantanol 2.6 parts, ethylbenzene 100 parts, charged with concentrated sulfuric acid 0 .8 parts was added and heated to reflux for 30 hours. After cooling, the mixture was filtered, and the filtration residue was washed with tert-butyl methyl ether to obtain 5.5 parts of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. As a result of analysis by ¹ H-NMR, since the inorganic salt was not removed, the content was 49.1%.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.84 (d, 2H); 2.00 (d, 2H); 2.29-2.32 (m , 7H); 2.54 (s, 2H)

(3) Difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt (5.0 parts, content: 49.1%) was added and chloroform (50.0 parts) was added. To this suspension, 42.0 parts (concentration 5.0%) of an aqueous methyldiphenylsulfonium chloride solution was added. After stirring for 15 hours, the mixture was separated, and the aqueous layer was extracted with 25.0 parts of chloroform. The organic layers were combined and washed repeatedly with ion-exchanged water until neutral, and the resulting organic layer was concentrated. The concentrated solution was decanted after adding 29.6 parts of tert-butyl methyl ether and stirring. 16.6 parts of ethyl acetate was added to the residue and stirred, followed by decantation to obtain 1.6 parts of methyldiphenylsulfonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (B4) as a pale yellow liquid.

¹ H-NMR (dimethylsulfoxide-d ₆ ): δ (ppm) 1.82 (d, 2H); 1.99 (d, 2H); 2.21-2.35 (m, 7H); 2.52 (S, 2H); 3.81 (s, 3H); 7.67-7.79 (m, 6H); 8.01-8.06 (m, 4H)

Acid generator synthesis example 5: Synthesis of acid generator B5 (1) 460 parts of a 30% aqueous sodium hydroxide solution was added dropwise to 200 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 300 parts of ion-exchanged water in an ice bath. The mixture was refluxed at 100 ° C. for 2.5 hours, cooled, and neutralized with 175 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 328.19 parts of difluorosulfoacetic acid sodium salt (the content was 62.8% because the inorganic salt was not removed).
(2) Difluorosulfoacetate sodium salt obtained in (1) 5.0 parts (content 62.8%), 4-oxo-1-adamantanol 2.6 parts, ethylbenzene 100 parts, charged with concentrated sulfuric acid 0 .8 parts was added and heated to reflux for 30 hours. After cooling, the mixture was filtered, and the filtration residue was washed with tert-butyl methyl ether to obtain 5.5 parts of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. As a result of analysis by ¹ H-NMR, the content was 57.6% because the inorganic salt was not removed.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.84 (d, 2H); 2.00 (d, 2H); 2.29-2.32 (m , 7H); 2.54 (s, 2H)

(3) 4.3 parts of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt (content 57.6%) was added and 43.0 parts of chloroform were added. To this suspension solution, 2.2 parts of a sulfonium salt (G1) and 11.7 parts of ion-exchanged water were added. Liquid separation was carried out after stirring for 15 hours, washing was repeated until the organic layer became neutral with ion-exchanged water, and the obtained organic layer was concentrated. The concentrated solution was decanted after adding 15.0 parts of tert-butyl methyl ether and stirring. The residue was dried to obtain 2.3 parts of Compound B5 as a white solid.

¹ H-NMR (dimethyl sulfoxide-d ₆ ): δ (ppm) 1.82 (d, 2H); 1.98 (d, 2H); 2.27-2.35 (m, 7H); 2.51 (S, 2H); 7.52 (d, 4H); 7.74-7.89 (m, 20H); 7.91 (d, 4H)

Acid generator synthesis example 6: Diphenyliodonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (acid generator B6) synthesis compound (G2) 4.0 parts, compound (G3) 9.6 parts (purity 50 0.1%), 96 parts of chloroform and 48 parts of ion-exchanged water were mixed and stirred overnight. After the reaction, the aqueous layer was separated after standing. The organic layer was repeatedly washed with 48 parts of ion-exchanged water until the aqueous layer became neutral. 1.4 parts of activated carbon was added to the organic layer, stirred and filtered. The filtrate was concentrated, 26 parts of tert-butyl methyl ether was added and stirred, and the precipitated white solid was filtered off and dried to obtain 4.3 parts of (B6).

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.82 (d, 2H, J = 12.7 Hz); 1.99 (d, 2H, J = 12. 2.28-2.36 (m, 7H); 2.52 (s, 2H); 7.52 (t, 4H, J = 7.4); 7.66 (dd, 2H, J = 1.2 Hz, 7.4 Hz); 8.24 (dd, 4H, J = 1.3, 8.4)

Acid generator synthesis example 7: Synthesis of dimethylphenylsulfonium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator B7) (1) 200 parts of difluoro (fluorosulfonyl) acetic acid methyl ester, 300 parts of ion-exchanged water, and ice bath Then, 460 parts of a 30% aqueous sodium hydroxide solution was added dropwise. The mixture was refluxed at 100 ° C. for 2.5 hours, cooled, and neutralized with 175 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 328.19 parts of difluorosulfoacetic acid sodium salt (the content was 62.8% because the inorganic salt was not removed).
(2) 123.3 parts of difluorosulfoacetic acid sodium salt (content 62.8%), 65.7 parts of 1-adamantane methanol and 600 parts of dichloroethane were added, 75.1 parts of p-toluenesulfonic acid was added, and 12 hours Heated to reflux. Thereafter, the mixture was concentrated to distill off dichloroethane, 400 parts of tert-butyl methyl ether was added, and after repulping, filtration was performed. After adding 400 parts of acetonitrile to the residue and stirring, filtration was repeated twice, and the filtrate was concentrated to obtain 99.5 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.51 (d, 6H); 1.62 (dd, 6H); 1.92 (s, 3H); 3.80 (s, 2H)

(3) Dissolve 5.0 parts of thioanisole in 15.0 parts of acetonitrile, add 8.35 parts of silver (I) perchlorate, and add 11.4 parts of acetonitrile of 5.71 parts of methyl iodide. And stirred for 24 hours. After the precipitated solid was removed by filtration, the filtrate was concentrated to remove acetonitrile. To the concentrated liquid, 36.8 parts of tert-butyl methyl ether was added and stirred, followed by filtration to obtain 8.22 parts of dimethylphenylsulfonium perchlorate as white crystals.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 3.25 (s, 6H); 7.67-7.80 (m, 3H); 8.03-8 .08 (m, 2H)

(4) 5.98 parts of difluorosulfoacetic acid-1-adamantyl methyl ester sodium salt obtained in (2) above was charged, and 35.9 parts of chloroform was added. To this suspension solution, 4.23 parts of dimethylphenylsulfonium perchlorate obtained in (3) above and 12.7 parts of ion-exchanged water were added. After stirring for 4 hours, the mixture was separated, and the aqueous layer was extracted with 23.9 parts of chloroform. The organic layers were combined and washed repeatedly with ion-exchanged water until neutral, and the resulting organic layer was concentrated. The concentrated solution was added with 31.8 parts of tert-butyl methyl ether, stirred and then filtered to obtain 5.38 parts of dimethylphenylsulfonium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (B7) as a white solid.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.51 (d, 6H); 1.62 (dd, 6H); 1.92 (s, 3H); 3.26 (s, 6H); 3.80 (s, 2H); 7.68-7.80 (m, 3H); 8.03-8.06 (m, 2H)
MS (ESI (+) Spectrum): M + 139.0 (C ₈ H ₁₁ S ⁺ = 139.06)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Acid Generator Synthesis Example 8: Synthesis of triphenylsulfonium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator B8) (1) Difluorosulfoacetic acid obtained by the same method as in Acid generator synthesis example 7 (2) -1-Adamantyl methyl ester 32.8 parts of sodium salt was charged and dissolved in 100 parts of ion-exchanged water. To this solution, 28.3 parts of triphenylsulfonium chloride and 140 parts of methanol were added. After stirring for 15 hours, the mixture was concentrated and extracted twice with 200 parts of chloroform. The organic layers were combined and washed repeatedly with ion-exchanged water until neutral, and the resulting organic layer was concentrated. The white precipitate obtained after adding and stirring 300 parts of tert-butyl methyl ether to the concentrated solution was filtered and dried under reduced pressure to obtain 39.7 of triphenylsulfonium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (B8) as white crystals. I got a part.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.52 (d, 6H); 1.63 (dd, 6H); 1.93 (s, 3H); 3.81 (s, 2H); 7.76-7.90 (m, 15H)
MS (ESI (+) Spectrum): M + 263.2 (C ₁₈ H ₁₅ S ⁺ = 263.09)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Synthesis Example 9 of Acid Generator: Synthesis of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator C1) (1) Methyl difluoro (fluorosulfonyl) acetate To 200 parts of ester and 300 parts of ion-exchanged water, 460 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The mixture was refluxed at 100 ° C. for 2.5 hours, cooled, and neutralized with 175 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 328.19 parts of sodium difluorosulfoacetate (containing inorganic salt, purity 62.8%).
(2) 123.3 parts of difluorosulfoacetic acid sodium salt (purity 62.8%), 65.7 parts of 1-adamantane methanol and 600 parts of dichloroethane were charged, and 75.1 parts of p-toluenesulfonic acid (p-TsOH) was added. In addition, the mixture was heated to reflux for 12 hours. Then, it concentrated, the dichloroethane was distilled off, 400 parts of tert-butyl methyl ether was added, it filtered after repulping. After adding and stirring 400 parts of acetonitrile to the residue, filtration was repeated twice and concentrated to obtain 99.5 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.51 (d, 6H); 1.62 (dd, 6H); 1.92 (s, 3H); 3.80 (s, 2H)

(3) 150 parts of 2-bromoacetophenone was dissolved in 375 parts of acetone, and 66.5 parts of tetrahydrothiophene was added dropwise. After stirring at room temperature for 24 hours, the obtained white precipitate was filtered, washed with acetone, and dried to obtain 207.9 parts of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium bromide as white crystals. It was.

¹ H-NMR (dimethylsulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 2.13-2.36 (m, 4H); 3.50-3.67 (m, 4H); 5 .41 (s, 2H); 7.63 (t, 2H); 7.78 (t, 1H); 8.02 (d, 2H)

(4) 99.5 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt obtained in (2) was charged and dissolved in 298 parts of acetonitrile. To this solution, 79.5 parts of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium bromide obtained in (3) above and 159 parts of ion-exchanged water were added. After stirring for 15 hours, the mixture was concentrated and extracted twice with 500 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. The concentrated solution was added with 250 parts of tert-butyl methyl ether, stirred, filtered, and dried under reduced pressure to give 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate as white crystals ( 116.9 parts of C1) were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.50 (d, 6H); 1.62 (dd, 6H); 1.92 (s, 3H); 2.13-2.32 (m, 4H); 3.45-3.63 (m, 4H); 3.80 (s, 2H); 5.30 (s, 2H); 7.62 (t, 2H); 7.76 (t, 1H); 8.00 (d, 2H)
MS (ESI (+) Spectrum): M + 207.0 (C ₁₂ H ₁₅ OS ⁺ = 207.08)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Synthesis Example 10 of Acid Generator: Synthesis of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 4-hydroxy-1-adamantyloxycarbonyldifluoromethanesulfonate (acid generator C2) (1) Difluorosulfoacetic acid 10.0 parts of -4-oxo-1-adamantyl ester sodium salt (purity 55.2%) was charged, and a mixed solvent of 30 parts of acetonitrile and 20 parts of ion-exchanged water was added. To this was added a solution of 5.0 parts 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium bromide, 10 parts acetonitrile, and 5 parts ion-exchanged water. After stirring for 15 hours, the mixture was concentrated and extracted with 98 parts of chloroform. The organic layer was washed with ion exchange water, and the obtained organic layer was concentrated. 4. Repulp the concentrate with 70 parts of ethyl acetate to give 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (C2) as a white solid. Two parts were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.83 (d, 2H, J = 12.5 Hz); 2.00 (d, 2H, J = 12. 0Hz); 2.21-2.37 (m, 11H); 2.53 (s, 2H); 3.47-3.62 (m, 4H); 5.31 (s, 2H); 7.63 (T, 2H, J = 7.3 Hz); 7.78 (t, 1H, J = 7.6 Hz); 8.01 (dd, 2H, J = 1.5 Hz, 7.3 Hz)
MS (ESI (+) Spectrum): M + 207.1 (C ₁₂ H ₁₅ OS ⁺ = 207.08)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₂ H ₁₃ F ₂ O ₆ S ⁻ = 323.04)

Acid Generator Synthesis Example 11: Synthesis of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate (acid generator C3) (1) In an ice bath, 25,000 parts of a 30% aqueous sodium hydroxide solution was added dropwise to 10000 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 15,000 parts of ion-exchanged water. The mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 7754 parts of concentrated hydrochloric acid. The obtained solution was concentrated, 6000 parts of acetonitrile was added to the obtained residue, and the mixture was stirred and filtered. The filtrate was concentrated and the resulting solid was filtered. The filtrate was concentrated, 200 parts of acetonitrile was added, and the mixture was stirred and filtered. To the obtained residue, 200 parts of acetonitrile was added, stirred, filtered and dried to obtain 605 parts of sodium difluorosulfoacetate salt compound (B8) (purity of 97.6% because inorganic salts were not removed).
(2) Difluorosulfoacetate sodium salt 5.6 parts (purity 97.6%) and N, N-dimethylformamide 16.7 parts were added with 1.45 parts of 1,1'-carbonyldiimidazole at 50 ° C. Stir for 2 hours. To this solution, 1.2 parts of sodium hydride was added to 5.0 parts of 3-hydroxyadamantyl methanol and 15.0 parts of N, N-dimethylformamide, and the mixture was stirred at 50 ° C. for 2 hours. did. After stirring at room temperature for 15 hours, the produced difluorosulfoacetic acid-3-hydroxy-1-adamantylmethyl ester sodium salt was directly used in the next reaction.

(3) To a solution of difluorosulfoacetic acid-3-hydroxy-1-adamantylmethyl ester sodium salt obtained in (2) above, 43.8 parts of chloroform, 1- (2-oxo-2-phenylethyl) tetrahydrothio 2.6 parts of fenium bromide and 13.0 parts of ion-exchanged water were added. After stirring for 15 hours, the mixture was separated, and the aqueous layer was extracted with 11.0 parts of chloroform. The organic layers were combined and washed repeatedly with ion-exchanged water until neutral, and the resulting organic layer was concentrated. To the concentrated solution, 23.4 parts of tert-butyl methyl ether was added and stirred, followed by filtration. To the filtration residue, 8.3 parts of ion-exchanged water was added, stirred and filtered to give 1- (2-oxo-2-phenyl) as a white solid 1.3 parts of ethyl) tetrahydrothiophenium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate (C3) were obtained.

¹ H-NMR of C3 (dimethylsulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.38-1.51 (m, 12H); 2.08 (S, 2H); 2.17 -2.26 (m, 4H); 3.45-3.63 (m, 4H); 3.85 (s, 2H); 4.42 (s, 1H); 5.30 (s, 2H); 7.62 (t, 2H); 7.77 (t, 1H); 8.00 (d, 2H)
MS (ESI (+) Spectrum): M + 207.0 (C ₁₂ H ₁₅ OS ⁺ = 207.08)
MS (ESI (−) Spectrum): M− 339.0 (C ₁₃ H ₁₇ F ₂ O ₆ S ⁻ = 339.07)

Synthesis Example of Acid Generator 12: Synthesis of 1- (2-oxo-2- (4′-methoxyphenylethyl)) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator C4) (1) 2 -50 parts of bromo-4'-methoxyacetophenone was dissolved in 150 parts of acetone, and 19 parts of tetrahydrothiophene was added dropwise. After stirring at room temperature for 24 hours, the resulting white precipitate was filtered, washed with acetone, and dried to give 1- (2-oxo-2- (4′-methoxyphenylethyl)) tetrahydrothiophenium bromide as white crystals. 63 parts were obtained.

¹ H-NMR (dimethylsulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 2.14-2.34 (m, 4H); 3.48-3.65 (m, 4H); 3 .89 (s, 3H); 5.39 (s, 2H); 7.15 (d, 2H, J = 8.9 Hz); 8.00 (d, 2H, J = 8.9 Hz)

(2) Preparation of acid generator C1 acid generator synthesis example (acid generator synthesis example 9) (2) of difluorosulfoacetic acid-1-adamantyl methyl ester sodium salt 3.05 parts obtained in the same manner And dissolved in 15.3 parts of acetonitrile. To this solution, 2.61 parts of 1- (2-oxo-2- (4′-methoxyphenylethyl)) tetrahydrothiophenium bromide obtained in (1) above and 13.1 parts of ion-exchanged water were added. did. After stirring for 15 hours, the mixture was concentrated and extracted twice with 50 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. The concentrated solution was added with 30 parts of tert-butyl methyl ether, stirred, filtered, and dried under reduced pressure to give 1- (2-oxo-2- (4′-methoxyphenylethyl)) tetrahydrothiophenium 1-adamantylmethoxy as white crystals. 3.44 parts of carbonyldifluoromethanesulfonate (C4) were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.52 (d, 6H); 1.63 (dd, 6H); 1.93 (s, 3H); 2.12-2.30 (m, 4H); 3.43-3.60 (m, 4H); 3.81 (s, 2H); 3.88 (s, 3H); 5.26 (s, 2H); 7.15 (d, 2H); 7.98 (d, 2H)
MS (ESI (+) Spectrum) : M + 237.2 (C 13 H 17 O 2 S + = 237.09)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Synthesis Example of Acid Generator 13: 1- (3,3-Dimethyl-2-oxobutyl) tetrahydrothiophenium Synthesis of 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator C5) (1) 70.2 parts of tetrahydrothiophene Was dissolved in 750 parts of acetone, and 150 parts of 1-bromo-3,3-dimethyl-2-butanone was added dropwise. After stirring at room temperature for 24 hours, the obtained white precipitate was filtered, washed with acetone, and dried to obtain 161.3 parts of 1- (3,3-dimethyl-2-oxobutyl) tetrahydrothiophenium bromide as white crystals. Got.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.14 (s, 9H); 2.08-2.30 (m, 4H); 3.37-3 .58 (m, 4H); 5.03 (s, 2H)

(2) Acid generator C1 acid generator synthesis example (acid generator synthesis example 9) (2) of difluorosulfoacetate-1-adamantylmethyl ester sodium salt obtained in 5.0 parts was charged with ion-exchanged water. Dissolved in 50 parts. To this solution, 3.86 parts of 1- (3,3-dimethyl-2-oxobutyl) tetrahydrothiophenium bromide obtained in (1) above and 19.3 parts of ion-exchanged water were added, and 50 parts of acetonitrile were added. Was added to obtain a completely dissolved system. After stirring for 15 hours, the mixture was concentrated and extracted twice with 100 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. 1- (3,3-Dimethyl-2-oxobutyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate as white crystals is obtained by adding 100 parts of tert-butyl methyl ether, stirring, filtering and drying under reduced pressure. 4.93 parts of (C5) were obtained.

¹ H-NMR (dimethylsulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.15 (s, 9H) 1.52 (d, 6H); 1.63 (dd, 6H); 1 .93 (s, 3H); 2.01-2.30 (m, 4H); 3.28-3.56 (m, 4H); 3.82 (s, 2H); 4.85 (s, 2H) )
MS (ESI (+) Spectrum): M + 187.2 (C ₁₀ H ₁₉ OS ⁺ = 187.12)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Resin Synthesis Example 1: Synthesis of Resin A1 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate, and α-methacryloyloxy-γ-butyrolactone were mixed with 5: 2.5: 2.5. The methyl isobutyl ketone was added 2 times by weight with respect to the total monomer to prepare a solution. Thereto, 2 mol% of azobisisobutyronitrile as an initiator was added with respect to the total amount of monomers and heated at 80 ° C. for about 8 hours. Thereafter, the operation of pouring the reaction solution into a large amount of heptane and precipitating was performed three times for purification. As a result, a copolymer having a weight average molecular weight of about 9200 was obtained. This copolymer has each unit represented by the following formula, and this is designated as resin A1.

Resin Synthesis Example 2: Synthesis of Resin A2 A molar ratio of 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate and 5-methacryloyloxy-2,6-norbornenelactone was 50:25:25 (3 .41 g: 6.38 g: 6.00 g), and 1,4-dioxane was added to the solution in an amount of 1.28 times the total monomers (32.86 g) to obtain a solution. Further, 3 mol% (0.532 g) of azobisisobutyronitrile as an initiator was added to make a solution. Separately, 1,2-dioxane was added in an amount of 0.72 times (18.72 g) of the total monomers, and then the temperature was raised to 88 ° C., and the monomer solution was charged therein at 88 ° C. for 2 hours. For 5 hours. After cooling the reaction mass, it was poured into a mixed solvent of a large amount of methanol and water, and the resulting precipitate was washed three times with a large amount of methanol, purified and dried. 16.3 g (yield 63.0%) of copolymer was obtained. This is called Resin A2.

Resin Synthesis Example 3: Synthesis of Resin A3 2-ethyl-2-adamantyl methacrylate, 1-ethylcyclohexyl methacrylate, 3-hydroxy-1-adamantyl methacrylate, 5-methacryloyloxy-2,6-norbornenelactone, α- Methacryloyloxy-γ-butyrolactone was charged at a molar ratio of 25: 20: 5: 20: 30 (23.00 g: 14.54 g: 4.38 g: 16.46 g: 18.91 g), and 1,4-dioxane was added thereto. Was added 1.3 weight times (100.47 g) of the total monomer to prepare a solution. Furthermore, 2.5 mol% (1.52 g) of azobisisobutyronitrile as an initiator was added to make a solution. Separately, 1.3 weight times (100.47 g) of 1,4-dioxane is added to the total monomers, and then the temperature is raised to 87 ° C., and the monomer solution is added thereto at 87 ° C. for 2 hours at the same temperature. For 6 hours. After the reaction mass was cooled, the reaction was precipitated three times with a large amount of methanol, purified and dried to obtain 55.5 g (yield 71.8%) of the following copolymer having an average molecular weight of about 9100. This is designated as resin A3.

Examples 1-14, Comparative Examples 1-7
The following components were mixed and dissolved, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist solution.

<Acid generator>
B1: Triphenylsulfonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate

B2: Triphenylsulfonium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate

B3: Triphenylsulfonium 1- (hexahydro-2-oxo-3,5-methano-2H-cyclopenta [b] furan-6-yloxycarbonyl) difluoromethanesulfonate

B4: Methyldiphenylsulfonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate

B5: (Oxydi-4,1-phenylene) bisdiphenylsulfonium bis (4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate)

B6: Diphenyliodonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate

B7: Dimethylphenylsulfonium 1-adamantylmethoxycarbonyldifluoromethanesulfonate

B8: Triphenylsulfonium 1-adamantylmethoxycarbonyldifluoromethanesulfonate

C1: 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate

C2: 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate

C3: 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate

C4: 1- (2-oxo-2- (4'-methoxyphenylethyl)) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate

C5: 1- (3,3-dimethyl-2-oxobutyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate

<Resin>
Types are listed in Table 1: 10 copies in total <quencher>
Q1: 2,6-diisopropylaniline <solvent composition>
Y1:
Propylene glycol monomethyl ether acetate 145 parts 2-heptanone 20.0 parts Propylene glycol monomethyl ether 20.0 parts γ-butyrolactone 3.5 parts

An organic antireflection film having a thickness of 780 mm is formed by applying a composition for organic antireflection film (ARC-29A; manufactured by Nissan Chemical Industries, Ltd.) to a silicon wafer and baking it at 205 ° C. for 60 seconds. I let you. Next, the resist solution described in Table 1 was spin-coated thereon so that the film thickness after drying was 0.15 μm. After applying the resist solution, pre-baking was performed on a direct hot plate at a temperature indicated in the column “PB” in Table 1 for 60 seconds. Using each ArF excimer stepper (FPA5000-AS3; manufactured by Canon Inc .; NA = 0.75 2 / 3Annular), the amount of exposure is changed stepwise on each wafer on which a resist film has been formed. Exposed.
After the exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature shown in the column of “PEB” in Table 1. Subsequently, development was performed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution.
The dark field pattern after development was observed with a scanning electron microscope on the organic antireflection film substrate, and the results are shown in Table 2. The dark field pattern referred to here is obtained by exposure and development through a reticle having a glass surface (translucent portion) formed in a line form on the outside with a chromium layer (light-shielding layer) as a base, and thus exposure development. The rest is a pattern in which the resist layer around the line and space pattern is left.

Effective sensitivity: The exposure was such that a 100 nm line and space pattern was 1: 1.
Line edge roughness evaluation: The surface of the resist pattern after the lithography process was observed with a scanning electron microscope, and Comparative Example 1 was used as a reference (indicated by Δ). Was judged as Δ, and the worsening was judged as ×.

[Table 1]
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example No. Resin Acid generator Quencher PB / PEB
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example 1 A1 / 10 part B1 / 0.30 part C1 / 0.60 part Q1 / 0.060 part 115 ° C / 115 ° C
Example 2 A1 / 10 part B1 / 0.40 part C1 / 0.30 part Q1 / 0.060 part 115 ° C / 115 ° C
Example 3 A1 / 10 part B1 / 0.40 part C2 / 0.30 part Q1 / 0.060 part 115 ° C / 115 ° C
Example 4 A2 / 10 part B1 / 0.40 part C1 / 0.30 part Q1 / 0.060 part 130 ° C / 125 ° C
Example 5 A1 / 10 part B8 / 0.40 part C1 / 0.30 part Q1 / 0.070 part 115 ° C / 115 ° C
Example 6 A1 / 10 part B3 / 0.40 part C1 / 0.30 part Q1 / 0.070 part 115 ° C / 115 ° C
Example 7 A1 / 10 part B5 / 0.60 part C1 / 0.30 part Q1 / 0.050 part 115 ° C / 115 ° C
Example 8 A1 / 10 part B7 / 0.40 part C1 / 0.30 part Q1 / 0.050 part 115 ° C / 115 ° C
Example 9 A1 / 10 part B1 / 0.40 part C4 / 0.30 part Q1 / 0.060 part 115 ° C / 115 ° C
Example 10 A3 / 10 part B1 / 0.40 part C1 / 0.30 part Q1 / 0.060 part 115 ° C / 105 ° C
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Comparative Example 1 A1 / 10 part B1 / 0.50 part Q1 / 0.060 part 115 ℃ / 115 ℃
Comparative Example 2 A1 / 10 part C1 / 1.50 part Q1 / 0.060 part 115 ° C / 115 ° C
Comparative Example 3 A2 / 10 part B1 / 0.50 part Q1 / 0.055 part 130 ° C / 125 ° C
Comparative Example 4 A2 / 10 part C1 / 1.20 part Q1 / 0.055 part 130 ° C / 125 ° C
Comparative Example 5 A1 / 10 part C4 / 1.50 part Q1 / 0.060 part 115 ° C / 115 ° C
Comparative Example 6 A3 / 10 part B1 / 0.50 part Q1 / 0.060 part 115 ° C / 105 ° C
Comparative Example 7 A2 / 10 part C2 / 0.50 part Q1 / 0.060 part 120 ° C / 120 ° C
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 2]
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example No. Effective sensitivity Resolution Pattern wall surface
(mJ / cm ² ) (nm) Smoothness ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example 1 29 90 ○
Example 2 29 90 ○
Example 3 31 90 ○
Example 4 24 90 ○
Example 5 33 90 ○
Example 6 37 90 ○
Example 7 33 90 ○
Example 8 28 90 ○
Example 9 33 90 ○
Example 10 30 90 ○
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Comparative Example 1 30 90 △
Comparative Example 2 34 95 ○
Comparative Example 3 24 90 ×
Comparative Example 4 29 95 △
Comparative Example 5 40 95 ○
Comparative Example 6 32 90 ×
Comparative Example 7 38 95 ×
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  Since the chemically amplified resist composition of the present invention gives excellent resolution and excellent line edge roughness, it should be used as a chemically amplified resist composition suitable for excimer laser lithography such as ArF and KrF and ArF immersion exposure lithography. In particular, it is suitable as a positive chemically amplified resist composition.

Claims (13)

An acid generator containing an onium salt represented by the formula (I) and a sulfonium salt represented by the formula (II), and a polymerized unit having an acid labile group, A chemically amplified resist composition comprising a resin that is insoluble or hardly soluble in water but becomes soluble in alkali by the action of an acid.

[In the formula (I), R ²¹ represents a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may be substituted, or a cyclic carbon atom having 3 to 30 carbon atoms which may be substituted. Represents a hydrogen group. However, the carbon atom contained in the hydrocarbon group and the cyclic hydrocarbon group may be optionally substituted with a carbonyl group or an oxygen atom.
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
A ⁺ represents at least one cation selected from the group consisting of cations represented by formula (Ia), formula (Ib) and formula (Ic).

[In Formula (Ia), P ^{1 to} P ³ each independently represents a linear, branched or cyclic hydrocarbon group having 1 to 30 carbon atoms. P ¹ if to P ³ is a linear or branched hydrocarbon group, a hydroxyl group, one or more of the substituents of the cyclic hydrocarbon group having 3 to 12 alkoxy group or a carbon number of 1 to 12 carbon atoms In the case where P ^{1 to} P ³ are cyclic hydrocarbon groups, one or more of a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms may be substituted. May be included. The hydrocarbon group and the alkoxy group may be linear or branched.
In formula (Ib), P ⁴ and P ⁵ each independently represent a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the hydrocarbon group and the alkoxy group The group may be linear or branched.
In formula (Ic), P ^{10 to} P ²¹ each independently represent a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the hydrocarbon group and the alkoxy group The group may be linear or branched.
B represents a sulfur atom or an oxygen atom.
m represents 0 or 1. ]

[In the formula (II), R ²² represents a linear or branched hydrocarbon group having 1 to 20 carbon atoms which may be substituted, or a cyclic carbon atom having 3 to 30 carbon atoms which may be substituted. Represents a hydrogen group. However, the carbon atom contained in the hydrocarbon group and the cyclic hydrocarbon group may be optionally substituted with a carbonyl group or an oxygen atom.
Q ³ and Q ⁴ each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
D ⁺ represents a cation represented by the formula (II ′).

[In Formula (II ′), P ⁶ and P ⁷ each independently represent a linear, branched or cyclic hydrocarbon group having 1 to 12 carbon atoms. Or ^{P 6} and ^{P 7} are bonded represent a divalent hydrocarbon group having 3 to 12 carbon atoms.
P ⁸ represents a hydrogen atom.
P ⁹ represents an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an optionally substituted aromatic ring group, or P ⁸ and P ⁹ are bonded to form 3 to 3 carbon atoms. 12 divalent hydrocarbon groups are represented. Here, the carbon atom contained in the divalent hydrocarbon group may be optionally substituted with a carbonyl group, an oxygen atom, or a sulfur atom. ] 2. The chemically amplified resist composition according to claim 1, wherein Q ^{1 to} Q ⁴ are each independently a fluorine atom or a trifluoromethyl group. The chemically amplified resist composition according to claim 1, wherein Q ^{1 to} Q ⁴ are fluorine atoms. The chemically amplified resist composition according to any one of claims 1 to 3, wherein A ⁺ in formula (I) is a cation represented by any of formula (Id), formula (Ie), or formula (If).

[In formulas (Id) to (If), P ^{28 to} P ³⁰ each independently represents a linear or branched hydrocarbon group having 1 to 20 carbon atoms, or a linear or branched carbon group. A C1-C12 cyclic hydrocarbon group other than a phenyl group is represented.
If P ²⁸ to P ³⁰ is a hydrocarbon group, a hydroxyl group may comprise as one or more substituents of the cyclic hydrocarbon group having 3 to 12 alkoxy group or a carbon number of 1 to 12 carbon atoms, If P ²⁸ to P ³⁰ is a cyclic hydrocarbon group, a hydroxyl group, it may be included as one or more of the substituents of the hydrocarbon group or an alkoxy group having 1 to 12 carbon atoms having 1 to 12 carbon atoms.
P ^{31 to} P ³⁶ each independently represent a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or a cyclic hydrocarbon group having 3 to 12 carbon atoms.
l, k, j, i, h and g each independently represent an integer of 0 to 5; ] The chemically amplified resist composition according to claim 1, wherein A ⁺ in formula (I) is a cation represented by formula (Ig).

[In the formula (Ig), P ^{41 to} P ⁴³ each independently represents a hydrogen atom, a hydroxyl group, a hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, The alkoxy group may be linear or branched. ] The chemically amplified resist composition according to claim 1, wherein A ⁺ in formula (I) is a cation represented by formula (Ih).

[In Formula (Ih), P ^{22 to} P ²⁴ each independently represent a hydrogen atom or a linear or branched hydrocarbon group having 1 to 4 carbon atoms. ] The chemically amplified resist composition according to any one of claims 1 to 6, wherein the onium salt represented by the formula (I) is an onium salt represented by the formula (Ii), the formula (Ij) or the formula (Ik). .

[In formula (Ii), formula (Ij) and formula (Ik), Q ¹ and Q ² represent the same meaning as in formula (I).
P ^{22 to} P ²⁴ represent the same meaning as in formula (Ih).
Ring X represents a monocyclic or polycyclic hydrocarbon group having 3 to 30 carbon atoms. However, the carbon atom of the hydrocarbon group may be substituted with a carbonyl group.
Ring X is a hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, a hydroxyl group, or a cyano group. It may be included as a substituent.
Z ¹ represents a single bond or [CH ₂ ] _k —.
k represents an integer of 1 to 4. ] The chemically amplified resist composition according to claim 1, wherein the onium salt represented by formula (I) is an onium salt represented by formula (Il), formula (Im), or formula (In). .

[In Formula (Il), Formula (Im), and Formula (In), Q ¹ and Q ² represent the same meaning as in Formula (I).
P ^{22 to} P ²⁴ represent the same meaning as in formula (Ih). ] The chemically amplified resist composition according to any one of claims 1 to 8, wherein the sulfonium salt represented by the formula (II) is a sulfonium salt represented by the formula (IIa), (IIb) or (IIc).

[In formulas (IIa), (IIb) and (IIc), P ^{6 to} P ⁹ , Q ³ and Q ⁴ represent the same meanings as in formulas (II) and (II ′).
Ring X is a substituent of a hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, a hydroxyl group, or a cyano group. May be included.
Z ² represents a single bond or a [CH ₂ ] _k -group.
k represents an integer of 1 to 4. ] The chemically amplified resist composition according to any one of claims 1 to 9, wherein the sulfonium salt represented by the formula (II) is a sulfonium salt represented by the formula (IId), the formula (IIe) or the formula (IIf). .

[In formulas (IId), (IIe) and (IIf), P ^{6 to} P ⁹ , Q ³ and Q ⁴ represent the same meanings as in formulas (II) and (II ′). ]   The acid generator is an acid generator containing an onium salt represented by the formula (I) and a sulfonium salt represented by the formula (II) in a weight ratio of 9: 1 to 1: 9. The chemically amplified resist composition according to any one of 1 to 10.   The chemically amplified resist composition according to claim 1, wherein the resin is a resin containing a structural unit derived from a monomer having a bulky group and an acid-labile group.   The chemically amplified resist composition according to any one of claims 1 to 12, further comprising a basic compound.